Among HIV-infected infants and children, the term "lateoutcomes" will be used generically to describe long-term consequences which may be related to HIV disease progression, treatment effects and/or an interaction of HIV disease and therapy. This is based on the rationale that distinguishing drug effects from disease effects may not always be possible. The term "late effects" will be used specifically to describe late consequences of antiretroviral therapies among perinatally treated infants who are ultimately proven not infected.